Spliced tow and process for making spliced tow

ABSTRACT

The ends of two tows or ropes of continuous filaments are overlapped and spliced together with a pneumatic tow-splicer or other means for interentangling the filaments, the sides of the tows are folded over adjacent to the splice to cover filament ends, and the filaments are interentangled with the tow-splicer to secure the folded over portions of tow. A strong, compact towsplice is obtained that is suitable for direct tow-to-sliver break-processing or for wet-drawing and crimping operations.

United States Patent [191 Meertens et a1.

SPLICED TOW AND PROCESS FOR MAKING SPLICED TOW Inventors: Jan Meertens,Dordrecht; Antonius H. J. Merkx, Hank, both of Netherlands E. l. du Pontde Nemours and Company, Wilmington, Del.

Filed: Jan. 30, 1974 Appl. No.: 437,858

Assignee:

US. Cl 57/142, 28/7212, 57/159 Int. Cl. B65h 69/06, D02j 1/08, D02g 3/22Field of Search 57/22, 142, 159; 28/72.12,

28/722 F, 1 CF, 1.4

References Cited UNITED STATES PATENTS 2/1967 Rosenstein 57/22 Feb. 25,1975 3,339,362 9/1967 Dodson, Jr. et al. 57/159 3,379,002 4/1968Rosenstein 57/142 3,458,905 8/1969 Dodson, Jr. et al. 57/22 X 3,619,86811/1971 Dibble 57/22 UX Primary ExaminerJohn Petrakes [57] ABSTRACT Theends of two tows or ropes of continuous filaments are overlapped andspliced together with a pneumatic tow-splicer or other means forinterentangling the filaments, the sides of the tows are folded overadjacent to the splice to cover filament ends, and the filaments areinterentangled with the tow-splicer to secure the folded over portionsof tow. A strong, compact towsplice is obtained that is suitable fordirect tow-tosliver break-processing or for wet-drawing and crimpingoperations.

3 Claims, 8 Drawing Figures SPLICED TOW AND PROCESS FOR MAKING SPLICEDTOW BACKGROUND OF THE INVENTION This invention relates to textile tow orrope splicing techniques and the resulting spliced product. By textile.tow or rope, hereinafter called tow, is meant a group of essentiallyparallel continuous textile filaments which individually are of textiledeniers but in aggregate total several thousand denier and in come caseshundreds of thousands denier.

During some steps in the production of textile tow from varioussynthetic polymers, such as polyacrylonitrile, finite lengths of tow arecollected in containers, lagged, andthen a multiplicity of containersplaced in a creel so that several tows are withdrawn and processed inparallel as a large aggregate tow. Since the length of tow in eachcontainer is-limited and may vary from container to container, splicingis required in order to achieve continuous processing. In otherinstances, such as for direct conversion of tow to staple sliver, it maybe necessary to combine at least two large tows prior to conversion,e.g., when using a Turbo Sta pler (Turbo Machine Co., Landsdale,Pennsylvania) or a Seydel Stretch Break Converter (Seydel & Co.,Germany). Component tows are usually furnished in finite lengths.Splicing in this case is also necessary to enable continuous processing.Conditions existent in various processing steps place demands on suchtow-splices for not only high strength (e.g., to withstand high drawingforces) but also low volume (e.g., to pass through crimping withadjacent unspliced tow).

In the past, many types of splices and splicing techniques have beendisclosed which involve sewing the splice with separate strands, addingadhesive to the splice area, or interentangling tow filaments in thesplice area with pneumatic or mechanical means, but the disclosedsplices have been too voluminous or too weak to satisfy the aboverequirements. Dodson et al. U.S. Pat. No. 3,339,362 discloses a processfor joining tows to form a continuous tow by placing the end of a tow Aover the end of atow B so that the filamentsof tow A rest on top of thefilaments of tow A with filaments of tow B to form a splice with opposedjets of air. Gagnon U.S. Pat. No. 3,308,520 discloses a similar processexcept that the filaments are mechanically interentangled by punchingfelting needles repeatedly through the overlapped ends of tow.

SUMMARY OF THE INVENTION The present invention is an improvement in thegeneral process described above; of placing the end of-a tow A over theend of a tow B so that the filaments of tow A rest on the filaments oftow B and interentangling the filaments of tow A with the filaments oftow B to form a preliminary splice. In accordance with the improvement,the assembly is then stretched laterally adjacent to the splice, oneedge of the tows is folded over toward or to the other edge of the towsto form an overlap at one side of the splice, the filaments areinterentangled at the overlap, the operation is repeated to form anoverlap in the tows on the other side of the preliminary splice, and thefilaments are interentangled at this overlap. The process provides astrong, compact, tow-splice. A stronger splice is provided when thefilaments are interentangled at several locations and in more than onedirection, as illustrated subsequently.

The invention provides compact splices in wet tow which remain intactduring wet-drawing at least about 4.5X followed by crimping. For thispurpose, the splice can be made in wet tow and water lost duringpneumatic interentanglement of filaments can be replaced by spraying thespliced tow with water. The invention provides compact splices in drytow which are suitable for direct tow-to-sliver break-processing.

BRIEF DESCRIPTION OF DRAWINGS FIGS. 1A through ID are schematicrepresentations of several steps involved in splicing an assembly of twotow ends by one embodiment of the invention; and

FIG. 2 is a schematic diagram of a second embodiment of the splice, withFIGS. 2A, 2B, and 2C providing sketches of cross-sectional views throughzones A, B, and C, respectively, of the splice of this type.

DESCRIPTIONS OF THE PREFERRED EMBODIMENTS Turning first to FIGS. 1Athrough 1D, the sequence of steps employed to provide the tow-splice ofthe first embodiment illustrating this invention are seen to corn prisethe following. In FIG. 1A, the terminal portion of a first tow 10 isplaced on a flat table with its end 1012 to the right, and that of a tow20 is placed so that it rests on top of the first tow but with its end20e about 40 centimeters to the left of end We The thus overlapped towsare grasped with both hands by an operator with one hand approximatelyat the location 20e and the other at the location We. This assembly isthen placed .in a pneumatic tow-splicer (such as that disclosed inDodson et al. U.S. Pat. 3,339,362) and a diagonal preliminary splice ismade from point I on one edge of the assembly to point II on the otheredge. In the illustrated embodiment, two parallel passes are made closetogether to provide a double diagonal preliminary splice.

Next, as shown in FIG. 1B, the end portions beyond the splice are thencut along lines parallel to and adjacent to the diagonal splice so thatnow the cut end of tow 20 is shown by a full diagonal line 20c and thatof tow 10 by a dotted diagonal line l0e', since it is on the undersideof the assembly. The next step is illustrated by FIG. 1C wherein the towassembly is grasped first at point I, stretched transversely withoutincurring splits in the tow, folded sidewise across the top of theremaining tow, and placed down on a point I directly across from theoriginal tow point I. A similar cross-fold is made by grasping the towat point II, stretching it sidewise and folding it over to position II',directly across the assembly. This new assembly is now placed back inthe pneumatic splicer and two splices 30, 31 are made directly acrossthe assembly at the location of the first foldover and two similarsplices 32, 33 are made at the location of the second foldover, Tocomplete this splice, pneumatic splices are made across the assemblystarting well to the left of the first foldover such as at line 40 inFIG. 1D and additional parallel, transverse, spaced splices (e.g., 41and 42) are made along the entire length of the folded portions andbeyond as illus hated by the transverse lines 40, 41', and 42'. Thislast set of splices (40, 41, 42, 40', 41', and 42') are typically spacedover a length of about 60 centimeters.

When this splice is made on wet tow, it is often necessary to furthermoisten the tow after this splicing has been completed by spraying withwater over the length of the splice and adjacent lengths that may havebecome partially dried.

Another tow-splice and splicing process embodying this invention isillustrated in FIG. 2. In this case, the terminal portions of first andsecond tows 110, 120 are laid down with the end 1l0e of the first tow onthe right and end 1202 of the second to the left and on top. The entireoverlap is made approximately 30 cm. long. The assembly is spread flatand each tow manipulated so that the tows are of equal width. Thisassemblage is grasped as before with both hands flat on the overlap, oneto the left and the other to the right of the middle, and the thus heldassembly placed in a pneumatic splicer of the type referenced above.Approximately three spaced splices are made directly across the assemblynear its middle, as shown by lines 115, and then cross diagonal splicesare added between the ends of the other splices as shown by the lines116. The assembly can now be released. A double foldover is carried outby pulling the edges transversely and then folding the assembly up overand partially across the assemblage from each edge. One set of foldoversis located to the left of the initial splice and spaced so that theactual end le of tow 120 is covered by the foldovers. This firstset offoldovers is now pneumatically spliced with a series of transverse andcross diagonal splices 140 and 141.

Next, the assembly is turned upside down and a similar double foldoverstructure made on the right in a position to enclose end 110e. This isnext spliced as described for the left hand set of foldovers.

The configuration of the completed tow splice is, further evident fromthe cross-sectional views of FIGS.

2A, 2B, and 2C. Thus, the left hand foldovers enclose two 120 inside towand the right hand foldovers enclose tow 110 inside tow 120, since theassembly was turned over before these latter foldovers were made.

The technology of this invention has been found to provide compacttow-splices that successfully pass through the steps of wet-drawing atleast about 4.5X followed by crimping. Furthermore, dry splicesaccording to this invention have been found to process satisfactorilythrough direct tow-to-sliver break-processing.

We claim:

1. In the process for joining tows to form a continuous tow by placingthe end of a tow A over the end of a tow B so that the filaments of towA rest on top of the filaments of tow B and interentangling filaments oftow A with filaments of tow B to form a splice, the improvement forforming a strong, compact tow-splice, wherein the improvement comprisesforming a preliminary splice, stretching the assembly laterally from oneedge adjacent to one side of the preliminary splice, folding thisstretched portion of the assembly over toward its other edge to form anoverlap at one side of the preliminary splice, interentangling filamentsat this overlap, similarly folding the assembly near the other side ofthe preliminary splice to form a second overlap at the other side of thepreliminary splice, and interentangling filaments at this secondoverlap.

2. A process as defined in claim 1, wherein the filaments are furtherinterentangled at intervals along the assembly at the location of thepreliminary splice and said overlaps.

3. Tow-spliced as defined in claim 1.

1. In the process for joining tows to form a continuous tow by placingthe end of a tow A over the end of a tow B so that the filaments of towA rest on top of the filaments of tow B and interentangling filaments oftow A with filaments of tow B to form a splice, the improvement forforming a strong, compact towsplice, wherein the improvement comprisesforming a preliminary splice, stretching the assembly laterally from oneedge adjacent to one side of the preliminary splice, folding thisstretched portion of the assembly over toward its other edge to form anoverlap at one side of the preliminary splice, interentangling filamentsat this overlap, similarly folding the assembly near the other side ofthe preliminary splice to form a second overlap at the other side of thepreliminary splice, and interentangling filaments at this secondoverlap.
 2. A process as defined in claim 1, wherein the filaments arefurther interentangled at intervals along the assembly at the locationof the preliminary splice and said overlaps.
 3. Tow-spliced as definedin claim 1.